Light emitting device, semiconductor device, and method of fabricating the devices

ABSTRACT

A semiconductor device in which degradation due to permeation of water and oxygen can be limited, e.g., a light emitting device having an organic light emitting device (OLED) formed on a plastic substrate, and a liquid crystal display using a plastic substrate. A layer to be debonded, containing elements, is formed on a substrate, bonded to a supporting member, and debonded from the substrate. A thin film is thereafter formed on the debonded layer. The debonded layer with the thin film is adhered to a transfer member. Cracks caused in the debonded layer at the time of debonding are thereby repaired. As the thin film in contact with the debonded layer, a film having thermal conductivity, e.g., film of aluminum nitride or aluminum nitroxide is used. This film dissipates heat from the elements and has the effect of preventing deformation and change in quality of the transfer member, e.g., a plastic substrate.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention:

[0002] The present invention relates to a semiconductor device having acircuit consisted of a thin film transistor (hereinafter, referred to asTFT) in which the peeled off layer peeled off has been pasted andtransferred on a base member and a method of manufacturing thesemiconductor device. For example, the present invention relates to anelectro-optic device that is represented by a liquid crystal module, alight emitting device that is represented by an EL module and anelectronic equipment on which such a device is mounted as a part.

[0003] It should be noted that in the present specification, the term“semiconductor device” indicates a device in general capable offunctioning by utilizing the semiconductor characteristics, and anelectro-optic device, a light emitting device, a semiconductor circuitand an electronic equipment are all semiconductor devices.

[0004] 2. Related Art:

[0005] In recent years, a technology constituting a thin film transistor(TFT) using a semiconductor thin film (in the range from about a few toa few hundreds nm in thickness) formed on the substrate having aninsulating surface has drawn attention. A thin film transistor is widelyapplied to electronic devices such as an IC, an electro-optic device orthe like, and particularly, there is an urgent need to be developed as aswitching element for an image display device.

[0006] Although as for applications utilizing such an image displaydevice, a variety of applications are expected, particularly, itsutilization for portable apparatuses has drawn the attention. Atpresent, although many glass substrates and quartz substrates areutilized, there are defaults of being easily cracked and heavy.Moreover, the glass substrates and quartz substrates are difficult to bemade larger in therms of conducting a mass-production, and these are notsuitable for that. Therefore, the attempt that a TFT element is formedon a substrate having flexibility, representatively, on a flexibleplastic film has been performed.

[0007] However, since the heat resistance of a plastic film is low, itcannot help lowering the highest temperature of the process. As aresult, at present, a TFT is formed which has not so excellent electriccharacteristics compared with those formed on the glass substrates.Therefore, a liquid crystal display device and light emitting elementhaving a high performance by utilizing a plastic film have not beenrealized yet.

[0008] If a light emitting device or a liquid crystal display deviceconstituted of an organic light emitting device (OLED) formed on aflexible substrate such as a plastic film can be fabricated, it can beobtained as a thin lightweight device and can be used in a displayhaving a curved surface, a show window, etc. Use of such a device is notlimited to use as a portable device, and the range of uses of such adevice is markedly wide.

[0009] However, substrates made of plastics ordinarily have permeabilityto water and oxygen, which act to accelerate degradation of the organiclight emitting layer. Therefore, light emitting devices using plasticsubstrates tend to have a shorter life. By considering this problem, amethod has been used in which an insulating film of silicon nitride orsilicon nitroxide is formed between a plastic substrate and an OLED toprevent mixing of water and oxygen in the organic light emitting layer.

[0010] Also, generally speaking, substrates formed of plastic film orthe like are not resistant to heat. If the temperature at which aninsulating film of silicon nitride or silicon nitroxide is formed on aplastic substrate is excessively high, the substrate deforms easily. Ifthe film forming temperature is excessively low, a reduction in filmquality results and it is difficult to effectively limit permeation ofwater and oxygen. There is also a problem in that when a device formedon a plastic film substrate or the like is driven, heat is locallyproduced to deform a portion of the substrate or to change the qualitythereof.

[0011] Further, if the thickness of the insulating film of siliconnitride or silicon nitroxide is increased in order to prevent permeationof water and oxygen, a larger stress is caused in the film and the filmcracks easily. If the film thickness is large, the film cracks easilywhen the substrate is bent. Also, a layer to be debonded may crack whenit is bent at the time of separation from the substrate.

SUMMARY OF THE INVENTION

[0012] In view of the above-described problems, an object of the presentinvention is to provide semiconductor device in which deterioration dueto permeation of water and oxygen can be limited, for example, a lightemitting device having an OLED formed on a plastic substrate or a liquidcrystal display device using a plastic substrate.

[0013] According to the present invention, a layer to be debonded,containing elements, is formed on a substrate, bonded to a supportingmember, and debonded from the substrate, a thin film is thereafterformed in contact with the debonded layer, and the debonded layer withthe thin film is adhered to a transfer member. The thin film is grown incontact with the debonded layer to repair cracks caused in the debondedlayer at the time of debonding. As the thin film in contact with thedebonded layer, a film having thermal conductivity, e.g., film ofaluminum nitride or aluminum nitroxide is used. This film dissipatesheat from the elements and therefore has the effect of limitingdegradation of the elements as well as the effect of preventingdeformation and change in quality of the transfer member 22, e.g., aplastic substrate. The film having thermal conductivity also has theeffect of preventing mixing of impurities such as water and oxygen fromthe outside.

[0014] An arrangement 1 of the present invention disclosed in thisspecification is a light emitting device characterized by having, on asubstrate having an insulating surface, a light emitting element havinga cathode, an organic compound layer in contact with the cathode, and ananode in contact with the organic compound layer, an insulating film incontact with the anode, and a film formed in contact with the insulatingfilm and having thermal conductivity.

[0015] An arrangement 2 of the present invention is a light emittingdevice characterized by having a substrate having an insulating surface,a bonding layer in contact with the substrate, a film formed in contactwith the bonding layer and having thermal conductivity and an insulatingfilm in contact with the film having thermal conductivity, and a lightemitting element formed on the insulating film, the light emittingelement having a cathode, an organic compound layer in contact with thecathode, and an anode in contact with the organic compound layer.

[0016] Each of the above-described arrangements is characterized in thatthe film having thermal conductivity comprises a film transparent ortranslucent to visible light.

[0017] Also, each of the above-described arrangements is characterizedin that the film having thermal conductivity is formed of a nitridecontaining aluminum, a nitroxide containing aluminum, or an oxidecontaining aluminum. As the film having thermal conductivity, amultilayer film formed of a combination of films of these materials maybe used. For example, a multilayer of aluminum nitride (AIN) andaluminum nitroxide (AlN_(X)O_(Y)(X>Y)), or a multilayer of aluminumnitroxide (AlN_(X)O_(Y)(X>Y)) and aluminum oxynitride(AlN_(X)O_(Y)(X<Y)) may be used.

[0018] Also, each of the above-described arrangements is characterizedin that the film having thermal conductivity comprises a film containingat least nitrogen and oxygen, and that the ratio of oxygen to nitrogenin the film is 0.1 to 30%.

[0019] Also, each of the above-described arrangements is characterizedin that the substrate having an insulating surface comprises a plasticsubstrate or a glass substrate.

[0020] An arrangement 3 of the present invention is a semiconductordevice characterized by having a transfer member, a first bonding layerin contact with the transfer member, a film formed in contact with thefirst bonding layer and having thermal conductivity, an insulating filmin contact with the film having thermal conductivity, a layer containingelements on the insulating layer, a second bonding layer (a sealingmaterial or the like) in contact with the layer containing elements, anda supporting member in contact with the second bonding layer.

[0021] In the above-described arrangement, it is characterized in thatif a liquid crystal display is fabricated, the supporting member is anopposed substrate, the elements are thinfilm transistors connected topixel electrodes, and a space between the pixel electrodes and thetransfer member is filled with a liquid crystal material. As thetransfer member and the opposed substrate, a plastic substrate or aglass substrate may be used.

[0022] An arrangement of the present invention relating to a method offabricating a semiconductor device for realizing the structure in eachof the above-described arrangements 1 to 3 includes:

[0023] a step of forming a nitride layer on a substrate;

[0024] a step of forming an oxide layer on the nitride layer;

[0025] a step of forming an insulating layer on the oxide layer;

[0026] a step of forming a layer containing elements on the insulatinglayer;

[0027] a step of bonding a supporting member to the layer containingelements, and thereafter debonding the supporting member from thesubstrate by a physical means at a position in the oxide layer or at aninterface on the oxide layer;

[0028] a step of forming a film having thermal conductivity on theinsulating layer or the oxide layer; and

[0029] a step of bonding a transfer member to the film having thermalconductivity to interpose the elements between the supporting member andthe transfer member.

[0030] In this specification, “physical means” refers to a meansrecognized not by chemistry but by physics, more specifically a dynamicmeans or mechanical means having a process capable of reducing to adynamic law, i.e., a means capable of changing some dynamic energy(mechanical energy). However, it is necessary that, at the time ofdebonding by a physical means, the strength of bonding between the oxidelayer and the nitride layer be smaller than the strength of bondingbetween the oxide layer and the supporting member.

[0031] The above-described arrangement relating to the method offabricating a semiconductor device is characterized in that the filmhaving thermal conductivity is formed of a nitride containing aluminum,a nitroxide containing aluminum, or an oxide containing aluminum. As thefilm having thermal conductivity, a multilayer film formed of acombination of films of these materials may be used.

[0032] The above-described arrangement relating to the method offabricating a semiconductor device is also characterized in that thenitride layer contains a metallic material, and that the metallicmaterial is a single layer of an element selected from the groupconsisting of Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os,Ir, and Pt, an alloy or a chemical compound having the element as a maincomponent, or a multilayer formed of such materials.

[0033] The above-described arrangement relating to the method offabricating a semiconductor device is also characterized in that a heattreatment or a treatment using irradiation with laser light is performedbefore debonding by the physical means.

[0034] The above-described arrangement relating to the method offabricating a semiconductor device is also characterized in that theoxide layer is a single layer of a silicon oxide material or a metallicoxide material, or a multilayer of these materials.

[0035] The above-described arrangement relating to the method offabricating a semiconductor device is also characterized in that theelements are thin-film transistors having a semiconductor layer as anactive layer, and that the step of forming the semiconductor layerincludes crystallizing a semiconductor layer of an amorphous structureby a heat treatment or a treatment using irradiation with laser light toobtain a semiconductor layer of a crystalline structure.

[0036] The above-described arrangement relating to the method offabricating a semiconductor device is also characterized in that if aliquid crystal display is fabricated, the supporting member is anopposed substrate, the elements have pixel electrodes, and a spacebetween the pixel electrodes and the opposed substrate is filled with aliquid crystal material.

[0037] In the above-described arrangement relating to the method offabricating a semiconductor device, if a light emitting device using anelement typified by an OLED is fabricated, it is desirable that thelight emitting element be completely isolated from the outside with thesupported member used as a sealing member to prevent materials such aswater and oxygen which accelerate degradation of an organic compoundlayer from entering from the outside. Specifically, in such a case, itis characterized in that the element is a light emitting element.

[0038] In each of the above-described arrangements, to facilitatedebonding, a heat treatment or a treatment using irradiation with laserlight may be performed before debonding by the physical means. In such acase, a material capable of absorbing laser light may be selected as thematerial of the nitride layer and the interface between the nitride andthe oxide may be heated to make separation easier. However, if laserlight is used, a transparent material is used to form the substrate.

[0039] To facilitate debonding, a granular oxide material may beprovided on the nitride layer and an oxide layer for covering thegranular oxide material may be provided , thus making separation easier.

[0040] The transfer member referred to in this specification is a memberbonded to the debonded layer after debonding. The base material of thetransfer member is not particularly specified. It may be a material ofany composition, e.g., plastic, glass, metal, or ceramics. Thesupporting member referred to in this specification is a member bondedto the layer to be debonded when the layer is debonded by a physicalmeans. The base material of the supporting member is not particularlyspecified. It may be a material of any composition, e.g., a plastic,glass, a metal, or a ceramic. The shape of the transfer member and theshape of the supporting member are not limited to a particular one. Eachof the transfer member and the supporting member may have a flat surfaceor a curved surface, may be flexible, and may have the shape of a film.If it is desirable to achieve a reduction in weight with the highestpriority, a plastic substrate in film form, e.g., a plastic substratemade of polyethylene terephthalate (PET), polyether sulfone (PES),polyethylene naphthalate (PEN), polycarbonate (PC), nylon,polyetheretherketone (PEEK), polysulfone (PSF), polyether imide (PEI),polyallylate (PAR), or polybutylene terephthalate (PBT) is preferred.

[0041] The present invention can be carried out without limiting thebonding method. Another arrangement relating to a method of fabricatinga semiconductor device for realizing the structure in each of theabove-described arrangements 1 to 3 includes:

[0042] a step of forming on a substrate a layer to be debondedcontaining elements;

[0043] a step of bonding a supporting member to the layer to bedebonded;

[0044] a step of debonding the supporting member from the substrate by aphysical means; and

[0045] a step of forming a film having thermal conductivity in contactwith the layer to be debonded.

[0046] As the debonding method in the above-described arrangements, awell-known technique can be used. Examples of such a technique are amethod in which a separation layer is provided between the layer to bedebonded and the substrate, and in which the separation layer is removedby a chemical solution (etchant) to separate the layer to be debondedfrom the substrate, and a method in which a separation layer formed ofan amorphous silicon (or polysilicon) is provided between the layer tobe debonded and the substrate, and in which the separation layer isirradiated with laser light passing through the substrate to releasehydrogen contained in the amorphous silicon, whereby a space forseparation between the layer to be debonded and the substrate is formed.In the case of separation using laser light, it is desirable that theelements contained in the layer to be debonded be formed by setting theheat treatment temperature to 410° C. or lower to avoid release ofhydrogen before debonding.

[0047] In this specification, “laser light” refers to laser lightgenerated from a laser light source, e.g., a solid-state laser such as aYAG laser or YVO₄ laser, or a gas laser such as an excimer laser. Themode of laser oscillation may be either of continuous oscillation orpulse oscillation. Any beam shape, e.g., line irradiation or spotirradiation may be used. Also, the scanning method is not particularlyspecified.

[0048] Still another arrangement relating to a method of fabricating asemiconductor device for realizing the structure in each of theabove-described arrangements 1 to 3 includes:

[0049] a step of forming on a substrate a layer to be debondedcontaining elements;

[0050] a step of bonding a supporting member to the layer to bedebonded;

[0051] a step of attaching a flexible printed circuit (FPC) to a portionof the layer to be debonded;

[0052] a step of fixing the supporting member by covering a connectionbetween the FPC and the layer to be debonded with an organic resin; and

[0053] a step of debonding the supporting member from the substrate by aphysical means.

[0054] The above-described arrangement includes, after the debondingstep, a step of forming a film having thermal conductivity in contactwith the debonded layer, and a step of bonding a transfer member to thefilm having thermal conductivity to interpose the debonded layer betweenthe supporting member and the transfer member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In the accompanying drawings:

[0056]FIGS. 1A, 1B, and 1C are diagrams showing fabricating steps inaccordance with the present invention;

[0057]FIGS. 2A, 2B, and 2C are diagrams showing fabricating steps inaccordance with the present invention;

[0058]FIGS. 3A, 3B, 3C, and 3D are diagrams showing TFT fabricatingsteps;

[0059]FIGS. 4A, 4B, 4C, and 4D are diagrams showing TFT fabricatingsteps;

[0060]FIG. 5 is a diagram showing an active matrix board beforeenclosure;

[0061]FIGS. 6A and 6B are an external view and a cross-sectional view,respectively, of an EL module;

[0062]FIG. 7 is a cross-sectional view of an EL module;

[0063]FIG. 8 is a cross-sectional view of an EL module;

[0064]FIGS. 9A, 9B, and 9C are diagrams showing a method of forming anorganic compound layer;

[0065]FIGS. 10A, 10B, and 10C are diagrams showing LCD fabricatingsteps;

[0066]FIGS. 11A and 11B are diagrams showing LCD fabricating steps;

[0067]FIG. 12 is a cross-sectional view of a half-transmission type ofliquid crystal display;

[0068]FIGS. 13A to 13F are diagrams showing examples of electronicequipment;

[0069]FIGS. 14A to 14C are diagrams showing examples of electronicequipment;

[0070]FIG. 15 is a graph showing the transmittance of AlN_(X)O_(Y) filmof the present invention;

[0071]FIG. 16 is a graph showing the results of ESCA analysis ofAlN_(X)O_(Y) film of the present invention;

[0072]FIG. 17 is a graph of a MOS characteristic (AlN_(X)O_(Y) film)with BT stress; and

[0073]FIG. 18 is a graph of a MOS characteristic (SiN film) with BTstress (comparative example).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0074] The present invention will be described with respect to anembodiment mode thereof.

[0075] The procedure of fabrication of a typical light emitting deviceusing the present invention will be briefly described with reference toFIGS. 1 and 2.

[0076]FIG. 1A illustrates a substrate 10, a nitride layer 11, an oxidelayer 12, a base insulating layer 13, elements 14 a to 14 c, an OLED 15,and an interlayer insulating film 16.

[0077] As the substrate 10 shown in FIG. 1A, a glass substrate, a quartzsubstrate, a ceramic substrate or the like may be used. A siliconsubstrate, a metallic substrate or a stainless substrate mayalternatively be used.

[0078] First, the nitride layer 11 is formed on the substrate 10, asshown in FIG. 1A. A nitride material containing a metallic material isused as the nitride layer 11. A typical example of the metallic materialis a single layer of an element selected from the group consisting ofTi, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os, Ir, and Pt,an alloy or a chemical compound having the element as a main component,or multiple layers of such materials. A single layer of a nitride of theelement, e.g., titanium nitride, tungsten nitride, tantalum nitride ormolybdenum nitride, or multiple layers of such materials may be used asthe nitride layer 11. A metallic layer formed of tungsten may be used inplace of the nitride layer 11.

[0079] Subsequently, the oxide layer 12 is formed on the nitride layer11. A typical example of a material used to form the oxide layer 12 issilicon oxide, silicon oxynitride or an oxide of a metal. To form theoxide layer 12, any of film forming methods such as sputtering, plasmaCVD and application may be used.

[0080] According to the present invention, it is important to make theoxide layer 12 and the nitride layer 11 have different film stresses.The film thickness of each layer is appropriately selected from therange of 1 to 1000 nm to adjust the film stress in the layer. While anexample of the structure in which the nitride layer 11 is formed incontact with the substrate 10 and which is selected for simplificationof the process is shown in FIG. 1, an insulating layer or a metalliclayer capable of functioning as a buffer layer may be formed between thesubstrate 10 and the nitride layer 11 to improve the adhesion to thesubstrate 10.

[0081] Subsequently, a layer to be debonded is formed on the oxide layer12. The layer to be debonded may be formed as a layer containing variouselements (a thin-film diode, a photoelectric conversion element having asilicon PIN junction, silicon resistance element, etc.) typified by aTFT. A heat treatment may be performed on the layers in such atemperature range that the substrate 10 can withstand. In the presentinvention, even though the film stress in the oxide layer 12 and thefilm stress in the nitride layer 11 are different, film separation orthe like is not caused by a heat treatment in the process of forming thelayer to be debonded. As the layer to be debonded, the elements 14 a and14 b for a drive circuit 23 and the element 14 c in a pixel portion 24are formed on the base insulating layer 13, the OLED 15 which connectselectrically to the element 14 of the pixel portion 24 is formed, andthe interlayer insulating film 16 having a thickness of 10 to 1000 nm isformed so as to cover the OLED (FIG. 1A).

[0082] If irregularities are formed in the surface after formation ofthe nitride layer 11 and the oxide layer 12, the surface may beflattened before or after the base insulating layer is formed.Flattening has the effect of improving coverage in the layer to bedebonded and, hence, the effect of stabilizing element characteristicsin the case where the layer to be debonded containing elements isformed. Therefore it is preferable to perform flattening. As a treatmentfor this flattening, etchback, i.e., flattening by etching or the likeafter formation of an applied film (resist film or the like), chemicalmechanical polishing (CMP), or the like may be performed.

[0083] Subsequently, a film 17 having thermal conductivity is formed onthe interlayer insulating film 16 (FIG. 1B). The film 17 having thermalconductivity may be formed adjacently to the OLED 15 instead of beingformed on the interlayer insulating layer 16. If the film 17 is formedadjacently to the OLED 15, it is preferred that the film 17 havingthermal conductivity be an insulating film. As the film 17 havingthermal conductivity, aluminum nitride (AlN), aluminum nitroxide(AlN_(X)O_(Y)(X>Y)), aluminum oxynitride (AlN_(X)O_(Y)(X<Y)), aluminumoxide (AlO) or beryllium oxide (BeO), for example, may be used. Ifaluminum nitroxide (AlN_(X)O_(Y)(X>Y)) is used, it is preferred that theratio of oxygen to nitride in the film be 0.1 to 30%. It is alsopreferred that the film 17 having thermal conductivity be a filmtransparent or translucent to visible light. In this embodiment mode, analuminum nitride (AlN) film having a light-transmitting property andhaving a markedly high thermal conductivity of 2.85 W/cm·K and an energygap of 6.28 eV (RT) is formed by sputtering. For example, an aluminumnitride (AIN) target is used and film forming is performed in anatmosphere in which argon gas and nitrogen gas are mixed. Alternatively,film forming may be performed in a nitrogen gas atmosphere by using analuminum (Al) target. The film 17 having thermal conductivity also hasthe effect of preventing materials such as water and oxygen whichaccelerate degradation of OLED 15 from entering from the outside.

[0084]FIG. 15 shows the transmittance of AlN_(X)O_(Y) film having athickness of 100 nm. As shown in FIG. 15, the light-transmittingproperty of the AlN_(X)O_(Y) film is markedly high (the transmittance inthe visible light region is 80 to 90%) and does not obstruct emission oflight from the light emitting element.

[0085] According to the present invention, the AlN_(X)O_(Y) film isformed by sputtering, for example, in an atmosphere in which argon gas,oxygen gas and nitrogen gas are mixed, with an aluminum nitride (AlN)used as a target. The AlN_(X)O_(Y) film may have several atomic percentor more, preferably 2.5 to 47.5 atm % of nitrogen. The nitrogenconcentration can be adjusted by suitably controlling sputteringconditions (substrate temperature, raw-material gas, gas flow rate, filmforming pressure, and the like). FIG. 16 shows the composition of theAlN_(X)O_(Y) film obtained in this manner and analyzed by electronspectroscopy for analysis (ESCA). Alternatively, film forming may beperformed in an atmosphere containing nitrogen gas and oxygen gas byusing an aluminum (Al) target. The film forming method is not limited tosputtering. Evaporation or any other known technique may be used.

[0086] To confirm the water/oxygen blocking effect of the AlN_(X)O_(Y)film, an experiment was made in which a sample having an OLED sealed ona film substrate with a 200 nm thick AlN_(X)O_(Y) film and a samplehaving an OLED sealed on a film substrate with a 200 nm thick SiN filmwere prepared and changes of the samples with time in a water vaporatmosphere heated at 85 degrees were examined. The life of the OLED inthe sample having the AlN_(X)O_(Y) film was longer than that of the OLEDin the sample having the SiN film. The former OLED was able to emitlight for a longer time. From the results of this experiment, it can beunderstood that the AlN_(X)O_(Y) film is more effective than the SiNfilm in preventing materials such as water and oxygen which acceleratedegradation of the organic compound layer from entering from the outsideof the apparatus. In addition, AlN and AlN_(X)O_(Y) are more difficultto crack than SiN. Therefore, A film formed of AlN or AlN_(X)O_(Y) ismore preferable than a film formed of SiN for attaching to a plasticsubstrate.

[0087] To confirm the alkali metal blocking effect of the AlN_(X)O_(Y)film, another experiment was made in which a 50 nm thick thermallyoxidized film was formed on a silicon substrate; a 40 nm thickAlN_(X)O_(Y) film was formed on the thermally oxidized film; an aluminumelectrode containing Li was formed on the AlN_(X)O_(Y) film; an aluminumelectrode containing Si was formed on the silicon substrate surfaceopposite from that surface on which the films were formed; and thesample was heat-treated at 300° C. for one hour and then underwent a BTstress test (±1.7 MV/cm, 150° C., 1 hour). A MOS characteristic (C-Vcharacteristic) was thereby measured. FIG. 17 shows the results of thisexperiment. In the C-V characteristic shown in FIG. 17, a shift in theplus direction occurred when a plus voltage, i.e., +BT, was applied. Itwas confirmed therefrom that the cause of the shift was not Li, and thatthe AlN_(X)O_(Y) film had an alkali metal blocking effect. Forcomparison, an AlLi alloy was formed on the MOS with an insulating film(100 nm thick silicon nitride film) interposed therebetween, and changesin MOS characteristic were also examined. FIG. 18 shows the results ofthis experiment. In the C-V characteristic shown in FIG. 18, a largeshift in the minus direction occurred when a plus voltage, i.e., +BT,was applied. It is thought that a major cause of this shift is mixtureof Li in the active layer.

[0088] A supporting member 19 for fixing the layer to be debonded toenable stripping of the substrate 10 by a physical means is adhered byusing a bonding layer 18 of an epoxy resin or the like (FIG. 1C). Thisstep is based on the assumption that the mechanical strength of thelayer to be debonded is not sufficiently high. If the mechanicalstrength of the layer to be debonded is sufficiently high, the layer tobe debonded can be debonded without a supporting member on which thelayer is fixed.

[0089] Subsequently, the substrate 10 on which the nitride layer 11 isformed is stripped off by a physical means. It can be stripped off by acomparatively small force since the film stress in the oxide layer 12and the film stress in the nitride layer 11 are different from eachother. While strength of bonding between the nitride layer and the oxidelayer is high enough to maintain bonding under thermal energy, the filmstresses in the nitride and oxide layers are different from each otherand a strain due to the stresses exists between the nitride and oxidelayers. Therefore, the bonding between the nitride and oxide layers isnot strong under dynamic energy and this condition is most suitable forseparation. Thus, the layer to be debonded, formed on the oxide layer12, can be separated from the substrate 10. FIG. 2A shows a state afterdebonding. This debonding method enables not only debonding of asmall-area layer to be debonded but also high-yield debonding throughthe entire area of a large-area layer to be debonded. Debonding can beperformed in the same manner even in a case where a metallic layerformed of tungsten is used in place of the nitride layer 11.

[0090] A film 20 having thermal conductivity is again formed on thesurface from which the substrate has been stripped off (FIG. 2B). Crackscaused at the time of debonding can be repaired by using the film 20having thermal conductivity. As the film 20 having thermal conductivity,aluminum nitride (AlN), aluminum nitroxide (AlN_(X)O_(Y) (X>Y)),aluminum oxynitride (AlN_(X)O_(Y) (X<Y)), aluminum oxide (AlO) orberyllium oxide (BeO), for example, may be used. It is preferred thatthe film 20 having thermal conductivity be a film transparent ortranslucent to visible light. In this embodiment mode, an aluminumnitride (AlN) film having a markedly high thermal conductivity of 2.85W/cm·K and an energy gap of 6.28 eV (RT) is formed by sputtering. Thefilm 20 having thermal conductivity also has the effect of preventingmaterials such as water and oxygen which accelerate degradation of OLED15 from entering from the outside.

[0091] The structure in which the OLED 15 is interposed between the twolayers of films 17 and 20 having thermal conductivity is thus formed tocompletely isolate the OLED 15 from the outside. However, a structure inwhich only one of the two layers of films 17 and 20 is formed mayalternatively be used.

[0092] The film thickness of each of the two layers of films 17 and 20having thermal conductivity be set as desired in the range of 20 nm to 4μm.

[0093] Subsequently, the debonded layer is attached to a transfer member22 by a bonding layer 21 such as an epoxy resin. In this embodimentmode, a plastic film substrate is used as the transfer member 22 inorder that the total weight of the light emitting device be reduced. Ifthe mechanical strength of the debonded layer is sufficiently high, itis not necessary to specially provide the transfer member.

[0094] Thus, the light emitting device having the OLED formed on theflexible plastic substrate is completed. Since in the structure of thislight emitting device, the elements 14 a to 14 c and the OLED 15 areinterposed between the two layers of films 17 and 20 having thermalconductivity, heat produced by the OLED 15 and the elements 14 a to 14 ccan be dissipated. The films 17 and 20 having thermal conductivity arealso capable of limiting degradation due to permeation of water andoxygen. If necessary, the supporting member or the transfer member iscut to be formed into a desired shape. A flexible printed circuit (FPC)(not shown) is attached to the debonded layer by using a well-knowntechnique. The FPC may be attached before debonding of the layer to bedebonded instead of being attached after debonding. Also, to increasethe mechanical strength of bonding between the FPC and the layer to bedebonded, an organic resin or the like may be formed to fix the FPC bycovering the bonding portion between the FPC and the layer to bedebonded.

[0095] The transfer member referred to in this specification is a memberbonded to the debonded layer after debonding. The base material of thetransfer member is not particularly specified. It may be a material ofany composition, e.g., a plastic, glass, a metal, or a ceramic. Thesupporting member referred to in this specification is a member bondedto the layer to be debonded when the layer is debonded by a physicalmeans. The base material of the supporting member is not particularlyspecified. It may be a material of any composition, e.g., a plastic,glass, a metal, or a ceramic. The shape of the transfer member and theshape of the supporting member are not limited to a particular one. Eachof the transfer member and the supporting member may have a flat surfaceor a curved surface, may be flexible, and may have the shape of a film.If weight saving is the top priority, a film-type plastic substrate, forexample, a plastic substrate including polyethylene terephthalate (PET),polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate(PC), nylon, polyetheretherketone (PEEK), polysulfone (PSF),polyetherimide (PEI), polyarylate (PAR), polybutylene terephthalate(PBT), or the like is preferable.

[0096] The present invention of the above-mentioned aspect is furtherillustrated in detail by the following Embodiments.

[0097] <Embodiment 1>

[0098] Embodiment of the present invention will be described withreference to FIGS. 3 to 5. In this embodiment, a method of manufacturingCMOS circuit at the same time, which is complementary combining ann-channel type TFT and a p-channel type TFT on a same substrate isexplained in detail.

[0099] First, the nitride layer 101, the oxide layer 102 and the baseinsulating film 103 are formed on the substrate 100, after asemiconductor film having a crystal structure was obtained, asemiconductor layers 104 to 105 isolated in a island shape are formed byetching processing in the desired shape.

[0100] As the substrate 100, the glass substrate (#1737) is used.

[0101] Moreover, as the metal layer 101, an element selected from Ti,Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os, Ir and Pt, or asingle layer consisted of alloy materials or compound materials whoseprincipal components are the foregoing elements or a lamination of thesemay be used. More preferably, a single layer consisted of thesenitrides, for example, titanium nitride, tungsten nitride, tantalumnitride, molybdenum nitride or a lamination of these may be used. Here,titanium nitride film having film thickness of 100 nm is utilized by asputtering method. Also, when the adhesion of the nitride layer 101 tothe substrate 100, a buffer layer may be provided therebetween.

[0102] Moreover, as the oxide layer 102, a single layer consisted of asilicon oxide material or a metal oxide material, or a lamination ofthese may be used. Here, a silicon oxide film having film thickness of200 nm by a sputtering method is used. The bond strength between thenitride layer 101 and the oxide layer 102 is strong in heat treatment,the film peeling (also referred to as solely “peeling”) or the like doesnot occur. However, it can be easily peeled off on the inside of theoxide layer or on the interface by the physical means.

[0103] Subsequently, as a base insulating layer 103, a siliconoxynitride film (composition ratio Si=32%, O=27%, N=24% and H=17%)prepared from the raw material gases SiH₄, NH₃, and N₂O was formed(preferably, 10 to 200 nm) in thickness of 50 nm at 400° C. of the filmformation temperature by a plasma CVD method. Subsequently, after thesurface was washed by ozone water, the oxide film of the surface wasremoved by dilute hydrofluoric acid (1:100 dilution). Subsequently, asilicon oxynitride film 103 b (composition ratio Si=32%, O=59%, N=7% andH=2%) prepared from the raw material gases SiH₄ and N₂O waslamination-formed in thickness of 100 nm (preferably, 50 to 200 nm) at400° C. of the film formation temperature by a plasma CVD method, andfurther, a semiconductor layer (here, an amorphous silicon layer) havingan amorphous structure was formed in thickness of 54 nm (preferably, 25to 80 nm) at 300° C. of the film formation temperature without the airrelease by a plasma CVD method.

[0104] In this embodiment, although the base film 103 is shown as atwo-layer structure, a single layer film of the foregoing insulatingfilm or a layer as a structure in which two layers or more are laminatedmay be formed. Moreover, there are no limitations to materials for asemiconductor film, but preferably, it may be formed using a silicon ora silicon germanium (Si_(x)Ge_(1−x)(X=0.0001-0.02)) alloy or the like bythe known methods (sputtering method, LPCVD method, plasma CVD method orthe like). Moreover, a plasma CVD apparatus may be single wafer typeapparatus, or batch type apparatus. Moreover, the base insulating filmand the semiconductor film may be continuously formed in the same filmformation chamber without contacting with the air.

[0105] Subsequently, after the surface of the semiconductor film havingan amorphous structure was washed, an oxide film having an extremelythin thickness of about 2 nm is formed on the surface with ozone water.

[0106] Next, nickel acetate solution containing 10 ppm of nickel in theweight conversion was coated by a spinner. A method of spreading overthe entire surface with nickel element by a sputtering method instead ofcoating may be employed.

[0107] Subsequently, a semiconductor film having a crystal structure wasformed by performing the heat treatment and crystallizing it. For thisheat treatment, the heat treatment of an electric furnace or theirradiation of strong light may be used. In the case where it isperformed by utilizing the heat treatment of the electric furnace, itmay be performed at 500° C. to 650° C. for 4 to 24 hours. Here, afterthe heat treatment (500° C., one hour) for dehydrogenation was carriedout, a silicon film having a crystal structure was obtained byperforming the heat treatment for crystallization (550° C., 4 hours). Itshould be noted that although here, crystallization was performed usingthe heat treatment by the furnace, however, the crystallization may beperformed by a lamp anneal apparatus. It should be noted that here, acrystallization technology using nickel as a metal element for promotingthe crystallization of silicon is used. However, the other knowncrystallization technology, for example, solid phase crystallizationmethod or laser crystallization method may be used.

[0108] Subsequently, after the oxide film of the surface of the siliconfilm having a crystal structure was removed by dilute hydrofluoric acidor the like, the irradiation of the first laser beam (XeCl: wavelength308 nm) for enhancing the crystallization ratio and repairing thedefaults remained within the crystal grain is performed in the air, orin the oxygen atmosphere. For a laser beam, an excimer laser beam of 400nm or less of wavelength, the second higher harmonic wave, the thirdhigher harmonic wave of YAG laser are used. When the pulse laser beamhaving about 10 to 1000 Hz of repeated frequency is used, the relevantlaser beam is condensed at 100 to 500 mJ/cm² by an optical system,irradiated with overlap ratio of 90 to 95% and it may be made it scanthe surface of the silicon film. Here, the irradiation of the firstlaser beam is performed at repeated frequency of 30 Hz, 393 mJ/cm² ofenergy density in the air. It should be noted that since it is performedin the air, or in the oxygen atmosphere, an oxide film is formed on thesurface by the irradiation of the first laser beam.

[0109] Subsequently, after the oxide film formed by irradiation of thefirst laser beam was removed by dilute hydrofluoric acid, theirradiation of the second laser beam is performed in the nitrogenatmosphere or in the vacuum, thereby flattening the surface of thesemiconductor film. For this laser beam (the second laser beam), anexcimer laser beam having a wavelength of 400 nm or less, the secondhigher harmonic wave, the third higher harmonic wave of YAG laser areused. The energy density of the second laser beam is made larger thanthe energy density of the first laser beam, preferably, made larger by30 to 60 mJ/cm². Here, the irradiation of the second laser beam isperformed at 30 Hz of the repeated frequency and 453 mJ/cm² of energydensity, P-V value (Peak to Valley, difference between the maximum valueand minimum value) of the concave and convex in the surface of thesemiconductor film is to be 50 nm or less. This P-V value is obtained byan AFM (atomic force microscope).

[0110] Moreover, in this embodiment, the irradiation of the second laserbeam was performed on the entire surface. However, since the reductionof the OFF-state current is particularly effective to the TFT of thepixel section, a step of selectively irradiating may be made on thepixel section at least.

[0111] Subsequently, a barrier layer consisted of an oxide film of total1 to 5 nm in thickness is formed by processing the surface with ozonewater for 120 seconds.

[0112] Subsequently, an amorphous silicon film containing argon elementwhich is to be gettering site is formed in film thickness of 150 nm onthe barrier layer by a sputtering method. The film formation conditionsby a sputtering method of this embodiment are made as 0.3 Pa of filmformation pressure, 50 (sccm) of gas (Ar) volumetric flow rate, 3 kW offilm formation power, and 150° C. of the substrate temperature. Itshould be noted that the atomic percentage of argon element contained inthe amorphous silicon film under the above-described conditions is inthe range from 3×10²⁰/cm³ to 6×10²⁰/cm³, the atomic percentage of oxygenis in the range from 1×10¹⁹/cm³ to 3×10¹⁹/cm³. Then, the gettering isperformed by carrying out the heat treatment at 650° C. for 3 minutesusing a lamp anneal apparatus.

[0113] Subsequently, after the amorphous silicon film containing argonelement that is the gettering site was selectively removed by using thebarrier layer as an etching stopper, the barrier layer is selectivelyremoved with dilute hydrofluoric acid. It should be noted that sincewhen gettering, nickel tends to easily move into the higher oxygendensity region, it is desirable that the barrier layer consisted of anoxide film is removed after the gettering. In this embodiment, anexample of conducting a gettering with argon element is shown, howeverit is not limited to this method. Another gettering method can also beused.

[0114] Subsequently, after a thin oxide film is formed with the ozonewater on the surface of the silicon film (also referred to as“polysilicon film”) having the obtained crystal structure, a maskconsisted of a resist is formed, and the semiconductor layers 104 and105 isolated in an island shape is formed in the desired shape byetching processing. After the semiconductor layer was formed, the maskconsisted of the resist is removed.

[0115] Subsequently, the oxide film was removed by an etchant containinghydrofluoric acid, and at the same time, the surface of the silicon filmwas washed, an insulating film whose principal component is silicon andwhich is to be a gate insulating film 106 is formed. In this embodiment,a silicon oxynitride film (composition ratio Si=32%, O=59%, N=7% andH=2%) is formed in thickness of 115 nm by plasma CVD method.

[0116] Subsequently, as shown in FIG. 3B, the first electricallyconductive film 107 having film thickness of 20 to 100 nm and the secondelectrically conductive film 108 having film thickness of 100 to 400 nmare lamination-formed on the gate insulating film 106. In thisembodiment, a tantalum nitride film having film thickness of 50 nm and atungsten film having film thickness of 370 nm are laminated sequentiallyon the gate insulating film 106.

[0117] As an electrically conductive material for forming the firstelectrically conductive film and the second electrically conductivefilm, it is formed using an element selected from Ta, W, Ti, Mo, Al andCu, or alloy material or compound material whose principal component isthe foregoing element. Moreover, as the first electrically conductivefilm and the second electrically conductive film, a semiconductor filmrepresented by a polycrystal silicon film in which impurity element suchas phosphorus or the like is doped, and AgPdCu alloy may be used.Moreover, it is not limited to a two-layer structure. For example, itmay be made a three-layer structure in which a tungsten film having filmthickness of 50 nm, aluminumsilicon (Al-Si) alloy having film thicknessof 500 nm, and a titanium nitride film having film thickness of 30 nmare in turn laminated. Moreover, in the case of a three-layer structure,instead of tungsten of the first electrically conductive film, tungstennitride may be used, instead of aluminum-silicon (Al-Si) alloy of thesecond electrically conductive film, aluminum-titanium (Al-Ti) alloyfilm may be used, or instead of a titanium nitride film of the thirdelectrically conductive film, a titanium film may be used. Moreover, itmay be a single layer structure.

[0118] Next, as shown in FIG. 3C, mask 109 consisted of resists areformed by light exposure step, the first etching processing for forminga gate electrode and wirings is performed. As for an etching, ICP(Inductively Coupled Plasma) etching method may be used. The film can beetched in the desired tapered shape by appropriately adjusting theetching conditions (electric energy applied to the coil type electrode,electric energy applied to the electrode on the substrate side,temperature of electrode on the substrate side and the like). It shouldbe noted that as gas for an etching, chlorine based gas which isrepresented by Cl₂, BCl₃, SiCl₄, CCl₄ or the like, fluorine based gaswhich is represented by CF₄, SF₆, NF₃ or the like or O₂ can beappropriately used.

[0119] Under the first conditions given above, the edges of the filmscan be tapered owing to the shape of the resist mask and the effect ofthe bias voltage applied to the substrate side. The angle of the taperedportion is set to 15 to 45°. In order to etch the films without leavingany residue on the gate insulating film, the etching time is prolongedby about 10 to 20%. The selective ratio of the silicon oxynitride filmto the W film is 2 to 4 (typically, 3), and hence the exposed surface ofthe silicon oxynitride film is etched by about 20 to 50 nm through theover-etching treatment. Through the first etching treatment, first shapeconductive layers 110 and 111 (first conductive layers 110 a and 111 aand second conductive layers 110 b and 111 b) are formed from the firstconductive film and the second conductive film. Denoted by 112 is a gateinsulating film and a region of the gate insulating film which is notcovered with the first shape conductive layers is etched and thinned byabout 20 to 50 nm.

[0120] Then the first doping treatment is performed to dope the filmwith an n type impurity (donor) as shown in FIG. 3D. The doping is madeby ion doping or ion implantation. In ion doping, the dose is set to1×10¹³ to 5×10¹⁴ atoms/cm². Used as the impurity element for impartingthe n type conductivity is a Group 5 element, typically phosphorus (P)or arsenic (As). In this case, the first shape conductive layers 110 and111 serve as masks against the element used for the doping and theacceleration voltage is adjusted appropriately (20 to 60 keV, forexample). The impurity element thus passes through the gate insulatingfilm 112 to form impurity regions (n+ region) 113 and 114. Thephosphorus (P) concentration in first impurity regions (n+ region) isset to 1×10²⁰ to 1×10²¹ atoms/cm³.

[0121] Then the second doping treatment is carried out as shown in FIG.4A. This time, the film is doped with an n-type impurity (donor) in adose smaller than in the first doping treatment at a high accelerationvoltage. For example, the acceleration voltage is set to 70 to 120 keVand the dose is set to 1×10¹³ atoms/cm³. As a result, impurity regionsare formed inside the first impurity regions that have been formed inthe island-like semiconductor films in FIG. 3D. In the second dopingtreatment, the second conductive films 110 b and 111 b are used as masksagainst the impurity element and the impurity element reaches regionsbelow the first conductive films 110 a and 111 a. Thus formed areimpurity regions (n-region) 115 and 116 that overlap the firstconductive films 110 a and 111 a, respectively. Since the remainingfirst conductive layers 110 a and 111 a have almost the uniformthickness, the concentration difference along the first conductivelayers is not large and the concentration in the impurity regions is1×10¹⁷ to 1×10¹⁹ atoms/cm³.

[0122] The second etching treatment is then conducted as shown in FIG.4B. In this etching treatment, ICP etching is employed, CF₄ and Cl₂ andO₂ are mixed as etching gas, and plasma is generated by giving RF (13.56MHz) power of 500 W to a coiled electrode at a pressure of 1 Pa. RF(13.56 MHz) power of 50 W is also given to the substrate side (samplestage) so that a self-bias voltage lower than that of the first etchingtreatment can be applied. The tungsten film is subjected to anisotropicetching under these conditions so that the tantalum nitride film or thetitanium film serving as the first conductive layers is remained. Inthis way, second shape conductive layers 117 and 118 (first conductivefilms 117 a and 118 a and second conductive films 117 b and 118 b) areformed. Denoted by 119 is a gate insulating film and a region of thegate insulating film which is not covered with the second shapeconductive layers 117 and 118 is further etched and thinned by about 20to 50 nm.

[0123] Then a resist mask 120 is formed as shown in FIG. 4C so that theisland-like semiconductor layer for forming the p-channel TFT is dopedwith a p type impurity (acceptor). Typically, boron (B) is used. Theimpurity concentration in impurity regions (p+ region) 121 and 122 isset to 2×10²⁰ to 2×10²¹ atoms/cm³. Thus the regions are doped with boronin a concentration 1.5 to 3 times higher than the concentration ofphosphorus that has already been contained in the regions, therebyinverting the conductive type of the regions.

[0124] The impurity regions are formed in each semiconductor layerthrough the above steps. The second shape conductive layers 117 and 118serve as gate electrodes. Thereafter, as shown in FIG. 4D, a protectiveinsulating film 123 is formed of a silicon nitride film or a siliconoxynitride film by plasma CVD. The impurity elements that is doped thesemiconductor layers are then activated for controlling the conductivitytype.

[0125] A silicon nitride film 124 is formed and subjected tohydrogenation. Hydrogen is released from the silicon nitride film 124 asa result and hydrogen diffuses to the semiconductor layers. Thesemiconductor layers are thus hydrogenated.

[0126] An interlayer insulating film 125 is formed of an organicinsulating material such as polyimide and acrylic. A silicon oxide filmformed by plasma CVD using TEOS may of course be adopted instead, but itis desirable to choose the above organic insulating material from theviewpoint of improving levelness.

[0127] Contact holes are formed next, so that source or drain wirings126 to 128 are formed from Al, Ti, Ta or the like.

[0128] In accordance with the above processes, a CMOS circuit obtainedby combining an n-channel TFT and a p-channel TFT complementally isobtained

[0129] A p-channel TFT has a channel formation region 130, and has theimpurity regions 121 and 122 that function as source regions or drainregions.

[0130] A n-channel TFT has a channel formation region 131; an impurityregion 116 a (gate overlapped drain: GOLD region) overlapping the gateelectrode 118 that is formed of the second shape conductive layer; animpurity region 116 b (LDD region) formed outside the gate electrode;and an impurity region 119 functioning as a source region or a drainregion.

[0131] The CMOS TFT as such can be used to form a part of a drivercircuit of an active matrix light emitting device or an active matrixliquid crystal display device. Besides, the n-channel TFT or thep-channel TFT as above can be applied to a transistor for forming apixel section.

[0132] Using the CMOS circuits of this embodiment in combination, abasic logic circuit or a more intricate logic circuit (such as a signaldivider circuit, a D/A converter, an operation amplifier and a γcorrection circuit) can be formed. It also can constitute a memory or amicroprocessor.

[0133] <Embodiment 2>

[0134] An example of fabrication of a light emitting device having anOLED and using the TFTs obtained in accordance with Embodiment 1 will bedescribed with reference to FIG. 5.

[0135]FIG. 5 shows an example of a light emitting device (in a statebefore sealing) having a pixel portion and a drive circuit for drivingthe pixel portion, the pixel portion and the drive circuit being formedon one insulating member. A CMOS circuit forming a basic unit in thedrive circuit and one pixel in the pixel portion are illustrated. TheCMOS circuit can be obtained in accordance with Embodiment 1.

[0136] Referring to FIG. 5, a substrate 200, a nitride layer 201 and anoxide layer 202 are provided. On a base insulating layer 203 formed onthe element formation substrate, the drive circuit 204 constituted of ann-channel TFT and a p-channel TFT, a switching TFT, which is a p-channelTFT, and a current control TFT, which is an n-channel TFT, are formed.In this embodiment, each of the TFTs is formed as a top gate TFT.

[0137] The n-channel TFT and p-channel TFT are the same as those inEmbodiment 1. The description for them will not be repeated. Theswitching TFT is a p-channel TFT of a structure having two channelforming regions between a source region and a drain region (double-gatestructure). In this embodiment, the structure of the switching TFT isnot limited to the double-gate structure, and the switching TFT mayalternatively have a single-gate structure in which only one channelforming region is formed or a triple-gate structure in which threechannel forming regions are formed.

[0138] A contact hole is formed in a first interlayer insulating film207 above the drain region 206 of the current control TFT before asecond interlayer insulating film 208 is formed. This is for the purposeof simplifying the etching step when a contact hole is formed in thesecond interlayer insulating film 208. A contact hole is formed in thesecond interlayer insulating film 208 so as to reach the drain region206, and a pixel electrode 209 connected to the drain region 206 isformed in the contact hole. The pixel electrode 209 functions as thecathode of the OLED and is formed by using a conductive film containingan element belonging to the group I or II in the periodic table. In thisembodiment, a conductive film of a compound composed of lithium andaluminum is used.

[0139] An insulating film 213 is formed so as to cover an end portion ofthe pixel electrode 209. The insulating film 213 will be referred to asa bank in this specification. The bank 213 may be formed of aninsulating film containing silicon or a resin film. If a resin film isused, carbon particles or metal particles may be added to set thespecific resistance of the resin film to 1×10⁶ to 1×10¹² Ωm (preferably1×10⁸ to 1×10¹⁰ Ωm), thereby reducing the possibility of dielectricbreakdown at the time of film forming.

[0140] The OLED 210 is formed by the pixel electrode (cathode) 209, anorganic compound layer 211, and an anode 212. As the anode 212, aconductive film of a large work function, typically an oxide conductivefilm is used. As this oxide conductive film, indium oxide, tin oxide,zinc oxide or some other compound of these elements may be used.

[0141] In this specification, “organic compound layer” is defined as ageneric name for a multilayer formed by combining with a light emittinglayer a hole injection layer, a hole transporting layer, a hole blockinglayer, an electron transporting layer, an electron injection layer, oran electron blocking layer. However, the organic compound layer maycomprise a single layer of organic compound film.

[0142] The material of the light emitting layer is an organic compoundmaterial but not limited to a particular one. It may be a high-molecularweight material or a low-molecular weight material. For example, a thinfilm formed of a light emitting material capable of emitting light byduplet excitation or a thin film formed of a light emitting materialcapable of emitting light by triplet excitation may be used as the lightemitting layer.

[0143] It is effective to form a passivation film (not shown) so as tocompletely cover the OLED 210 after the formation of the anode 212. Afilm having thermal conductivity, e.g., film of aluminum nitride,aluminum nitroxide, or beryllium oxide is suitably used as thepassivation film. Also, an insulating film comprising a diamondlikecarbon (DLC) film, a silicon nitride film or a silicon nitroxide film,or a multilayer formed of a combination of such films may be used as thepassivation film.

[0144] To protect the OLED 210, steps including a step for attaching asupporting member as described above with respect to the embodiment modeand a sealing (enclosing) step are performed. Thereafter, the substrate200 on which the nitride layer 201 is formed is stripped off. An exampleof the light emitting device after this step will be described withreference to FIGS. 6A and 6B. The transfer member 22 in FIG. 2Dcorresponds to a film substrate 600.

[0145]FIG. 6A is a top view of an EL module, and FIG. 6B is across-sectional view taken along the line A-A′ of FIG. 6A. Referring toFIG. 6A, a film 601 having thermal conductivity (e.g., aluminum nitridefilm) is formed on the flexible film substrate 600 (e.g., a plasticsubstrate), and a pixel portion 602, a source-side drive circuit 604,and a gate-side drive circuit 603 are formed on the film 601. The pixelportion and the drive circuits can be obtained in the same manner asthose described above with respect to Embodiments 1 and 2.

[0146] An organic resin 618 and a protective film 619 are provided. Thepixel portion and the drive circuit portions are covered with theorganic resin 618 and the surface of the organic resin 618 is coveredwith the protective film 619. These portions are enclosed with a covermember 620 using an adhesive. The cover member 620 is bonded as asupporting member before debonding of the element layer. It is desirablethat a member made of the same material as the film substrate 600, e.g.,a plastic substrate be used as the cover member 620, such that the covermember 620 is prevented from being deformed by heat or external force.For example, a member which is worked so as to form a cavity (having adepth of 3 to 10 μm) as shown in FIG. 6B is used. It is also desirablethat the cover member be further worked to form a recess (having a depthof 50 to 200 μm) capable of accommodating a desiccant 621. If the ELmodule is manufactured on a gang board, the gang board may be cut afterbonding between the substrate and the cover member. The gang board iscut with a CO₂ laser or the like so that end surfaces are aligned.

[0147] Wiring 608 is provided for transmission of signals input to thesource-side drive circuit 604 and the gate-side drive circuit 603. Avideo signal and a clock signal from a flexible printed circuit (FPC)609 provided as an external input terminal are received through thewiring 608. Although only the FPC is illustrated, a printed wiring board(PWB) may be attached to the FPC. The light emitting device described inthis specification comprises an arrangement including not only the lightemitting device main unit but also the FPC or PWB in the attached state.

[0148] The structure of the light emitting device as seen in a crosssection will next be described with reference to FIG. 6B. The film 601having thermal conductivity is formed on the film substrate 600, theinsulating film 610 is formed on the film 601, and the pixel portion 602and the gate-side drive circuit 603 are formed above the insulating film610. The pixel portion 602 is formed by a plurality of pixels includinga current control TFT 611 and a pixel electrode 612 electricallyconnected to the drain of the current control TFT 611. The gate-sidedrive circuit 603 is formed by using a CMOS circuit having a combinationof an n-channel TET 613 and a p-channel TFT 614.

[0149] These TFTs (611, 613, 614, etc.) may be fabricated in the samemanner as the n-channel TFT of Embodiment 1 and the p-channel TFT ofEmbodiment 1.

[0150] After the pixel portion 602, the source-side drive circuit 604and the gate-side drive circuit 603 have been formed on one substrate inaccordance with Embodiments 1 and 2, the supporting member (cover memberin this embodiment) is bonded, the substrate (not shown) is debonded,the film 601 (e.g., aluminum nitride film) having thermal conductivityis formed on the insulating film 610, and the film substrate 600 isthereafter adhered, as shown in FIG. 1C and FIG. 2A to 2C. A bondinglayer, which is not shown, is provided between the film 601 havingthermal conductivity and the film substrate 600 to bond these films toeach other.

[0151] In the case where the cover member 620 is formed so as to have acavity as shown in FIG. 6B, no portion of the supporting member existsadjacent to the insulating film 610 in the portion (connection portion)corresponding to the wiring lead-out terminal at the time of debondingof the element layer after bonding of the cover member 620 provided asthe supporting member, so that the mechanical strength of this portionis low. Therefore, it is desirable that the FPC 609 be attached beforedebonding and fixed by an organic resin 622.

[0152] In addition, as the insulating film provided between the TFT andthe OLED, a material which not only blocks diffusion of an impurity ionsuch as an alkali metal ion, an alkali earth metal ion, but alsoaggressively adsorbs the impurity ion such as an alkali metal ion and analkali earth metal ion may be preferable. Furthermore, a material whichresists the temperature in the following process may be more preferable.One example of the material suitable for these conditions includes asilicon nitride film containing fluorine in a large amount. Theconcentration of the fluorine contained in the silicon nitride film maybe 1×10¹⁹/cm³ or more, and preferably, the composition ratio of thefluorine in the silicon nitride film may be 1 to 5%. The fluorine in thesilicon nitride film binds to an alkali metal ion, an alkali earth metalion, or the like, which is adsorbed in the silicon nitride film. Anotherexample includes an organic resin film containing particles consistingof an antimony (Sb) compound, a tin (Sn) compound, or an indium (In)compound, which adsorbs an alkali metal ion, an alkali earth metal ion,or the like, e.g. an organic resin film including particles of antimonypentoxide (Sb₂O₅·nH₂O). This organic resin film includes particles withan average particle diameter of 10 to 20 nm, and the light transmittanceof this film is very high. The antimony compounds represented by theparticles of antimony pentoxide can easily adsorb the impurity ion suchas an alkali metal ion, and alkali earth metal ion.

[0153] The pixel electrode 612 functions as the cathode of the lightemitting device (OLED). Banks 615 are formed at opposite ends of thepixel electrode 612, and an organic compound layer 616 and an anode 617of the light emitting element are formed on the pixel electrode 612.

[0154] The organic compound layer 616 (for emission of light andmovement of carriers for causing emission of light) may be formed byfreely selecting a combination of a light emitting layer and a chargetransporting layer or a charge injection layer. For example, alow-molecular weight organic compound material or a high-molecularweight organic compound material may be used to form the organiccompound layer 616. Also, a thin film formed of a light emittingmaterial (singlet compound) capable of emission of light (fluorescence)by singlet excitation or a thin film formed of a light emitting material(triplet compound) capable of emission of light (phosphorescence) bytriplet excitation may be used as the organic compound layer 616. Aninorganic material such as silicon carbide may be used as a chargetransporting layer or a charge injection layer. These organic andinorganic materials may be selected from well-known materials.

[0155] The anode 617 also functions as a common wiring element connectedto all the pixels and is electrically connected to the FPC 609 viaconnection wiring 608. All the elements included in the pixel portion602 and the gate-side drive circuit 603 are covered with the anode 617,the organic resin 618 and the protective film 619.

[0156] It is preferred that a material higher in transparency ortranslucency to visible light be used as the organic resin 618. Also, itis desirable that a material higher in ability to limit permeation ofwater and oxygen be used as the organic resin 618.

[0157] Also, it is preferred that after the light emitting element hasbeen completely covered with the organic resin 618, the protective film619 be at least formed on the surface (exposed surface) of the organicresin 618 as shown in FIGS. 6A and 6B. The protective film may be formedon the entire surface including the back surface of the substrate. Insuch a case, it is necessary to carefully form the protective film sothat no protective film portion is formed at the position where theexternal input terminal (FPC) is provided. A mask may be used to preventfilm forming of the protective film at this position. The external inputterminal portion may be covered with a tape such as a tape made ofTeflon (registered trademark) used as a masking tape in a CVD apparatusto prevent film forming of the protective film. A film having thermalconductivity like the film 601 may be used as the protective film 619.

[0158] The light emitting element constructed as described above isenclosed with the film 601 having thermal conductivity and theprotective film 619 to completely isolate the light emitting elementfrom the outside, thus preventing materials such as water and oxygenwhich accelerate degradation of the organic compound layer by oxidationfrom entering from the outside. Also, the film having thermalconductivity enables dissipation of produced heat. Thus, the lightemitting device having improved reliability is obtained.

[0159] Another arrangement is conceivable in which a pixel electrode isused as an anode and an organic compound layer and a cathode are formedin combination to emit light in a direction opposite to the directionindicated in FIG. 6B. FIG. 7 shows an example of such an arrangement.This arrangement can be illustrated in the same top view as FIG. 6A andwill therefore be described with reference to a cross-sectional viewonly.

[0160] The structure shown in the cross-sectional view of FIG. 7 will bedescribed. An insulating film 710 is formed on a film substrate 700, anda pixel portion 702 and a gate-side drive circuit 703 are formed overthe insulating film 710. The pixel portion 702 is formed by a pluralityof pixels including a current control TFT 711 and a pixel electrode 712electrically connected to the drain of the current control TFT 711.After the layer to be debonded, which is formed on a substrate inaccordance with the above-described embodiment mode of the presentinvention, has been debonded, a film 701 having thermal conductivity isformed on the surface of the layer to be debonded. Further, the filmsubstrate 700 is adhered to the layer 701 having thermal conductivity. Abonding layer, which is not shown, is provided between the film 701having thermal conductivity and the film substrate 700 to bond thesefilms to each other. A gate-side drive circuit 703 is formed by using aCMOS circuit having a combination of an n-channel TET 713 and ap-channel TFT 714.

[0161] These TFTs (711, 713, 714, etc.) may be fabricated in the samemanner as the n-channel TFT 201 of Embodiment 1 and the p-channel TFT202 of Embodiment 1.

[0162] The pixel electrode 712 functions as an anode of the lightemitting device (OLED). Banks 715 are formed at opposite ends of thepixel electrode 712, and an organic compound layer 716 and a cathode 717of the light emitting element are formed over the pixel electrode 712.

[0163] The cathode 717 also functions as a common wiring elementconnected to all the pixels and is electrically connected to a FPC 709via connection wiring 708. All the elements included in the pixelportion 702 and the gate-side drive circuit 703 are covered with thecathode 717, an organic resin 718 and a protective film 719. A covermember 720 is bonded to the element layer by an adhesive. A recess isformed in the cover member and a desiccant 721 is set therein.

[0164] In the case where the cover member 720 is formed so as to have acavity as shown in FIG. 7, no portion of the supporting member existsadjacent to the insulating film 710 in the portion corresponding to thewiring lead-out terminal at the time of debonding of the element layerafter bonding of the cover member 720 provided as the supporting member,so that the mechanical strength of this portion is low. Therefore, it isdesirable that the FPC 709 be attached before debonding and fixed by anorganic resin 722.

[0165] In the arrangement shown in FIG. 7, the pixel electrode is usedas the anode while the organic compound layer and the cathode are formedin combination, so that light is emitted in the direction of the arrowin FIG. 7.

[0166] While the top gate TFTs have been described by way of example,the present invention can be applied irrespective of the TFT structure.For example, the present invention can be applied to bottom gate(inverted staggered structure) TFTs and staggered structure TFTs.

[0167] <Embodiment 3>

[0168] While an example of use of the top gate TFT in Embodiment 2 hasbeen described, a bottom gate TFT can also be used. An example of anarrangement using a bottom gate TFT will be described with reference toFIG. 8.

[0169] As shown in FIG. 8, each of an n-channel TFT 913, a p-channel TFT914, and an n-channel TFT 911 is of the bottom gate structure. The TFTsin the bottom gate structure may be fabricated by using well-knowntechniques. The active layer of these TFTs may be a semiconductor filmhaving a crystalline structure (e.g., polysilicon) or a semiconductorfilm having an amorphous structure (e.g., amorphous silicon).

[0170] In FIG. 8 are illustrated a flexible film substrate 900 (e.g., aplastic substrate), a film 901 having thermal conductivity (e.g.,aluminum nitride film), a pixel portion 902, a gate-side drive circuit903, an insulating film 910, a pixel electrode (cathode) 912, a bank915, an organic compound layer 916, an anode 917, an organic resin 918,a protective film 919, a cover member 920, a desiccant 921, and anorganic resin 922. A bonding layer, which is not shown, is providedbetween the film 901 having thermal conductivity and the film substrate900 to bond these films to each other.

[0171] The arrangement is the same as that of Embodiment 3 except forthe n-channel TFT 913, the p-channel TFT 914 and the n-channel TFT 911.The description of the same details will not be repeated.

[0172] <Embodiment 4>

[0173] In this embodiment, when an organic compound layer is formed byan ink jet method, the organic compound layer is continuously formedthrough a plurality of pixels. More specifically, an example offormation in which the organic compound layer is formed in a stripe formon each of columns or rows of pixel electrodes arranged incorrespondence with a matrix with m rows and n columns will bedescribed. Also, the organic compound layer is formed in an oblong orrectangular shape in correspondence with each pixel electrode.

[0174]FIGS. 9A, 9B, and 9C are diagrams illustrating this embodiment.FIG. 9A shows an arrangement in which a pixel portion 802, ascanning-line-side drive circuit 803 and a data-line-side drive circuit804 are provided on a substrate 801. A separation layer 805 is providedin the form of lands in a striped pattern in the pixel portion 802, andthe organic compound layer is formed between each adjacent pair of theseparation layer lands. The separation layer 805 is provided for thepurpose of preventing each adjacent pair of the organic compound layerportions from mixing when the organic compound layer is formed by an inkjet method.

[0175] The organic compound layer 806 is formed by jetting from an inkhead 807 a solution containing an organic compound material. Thematerial of the organic compound layer is not limited to a particularone. However, if a multicolor is performed, organic compound layers806R, 806G, and 806B may be provided in correspondence with red, greenand blue.

[0176]FIG. 9B is a cross-sectional view of the structure schematicallyshown in FIG. 9A, showing a state in which the scanning-line-side drivecircuit 803 and the pixel portion 802 are formed on the substrate 801.The lands of separation layer 805 are formed in the pixel portion 802,and organic compound layers 806R, 806G, and 806B are formed between theseparation layer lands. The ink head 807 is of an ink jet type. Inkdroplets 808R, 808G, and 808B corresponding to the colors, red, greenand blue are jetted from the ink head 807 according to a control signal.The jetted ink droplets 808R, 808G, and 808B are attached to the surfaceof the substrate and undergo drying and baking steps. Thereafter, thejetted materials function as the organic compound layers. The ink headmay be moved in one direction for scanning along each column or row, sothat the processing time required to form the organic compound layerscan be reduced.

[0177]FIG. 9C is a diagram showing the pixel portion in more detail.Current control TFTs 810 and pixel electrodes 812 connected to thecurrent control TFTs 810 are formed on the substrate, and the organiccompound layers 806R, 806G, and 806B are formed between the lands of theseparation layer 805 on the pixel electrodes. It is desirable that aninsulating film 811 having an alkali metal blocking effect be formedbetween the pixel electrodes 812 and the current control TFTs 810.

[0178] This embodiment can be applied as the method of forming theorganic compound layer in one of the embodiment mode, Embodiment 2 andEmbodiment 3.

[0179] <Embodiment 5>

[0180] In this embodiment, the step in which an active matrix typeliquid crystal display device is prepared by peeling off the substratefrom the active matrix substrate prepared in Embodiment 1 and adheringit with a plastic substrate will be described below. FIG. 10 is used forthe purpose of describing it.

[0181] In FIG. 10A, the reference numeral 400 denotes a substrate, thereference numeral 401 denotes a nitride layer, the reference numeral 402denotes an oxide layer, the reference numeral 403 denotes a baseinsulating layer, the reference numeral 404 a denotes an element of adriver circuit 413, the reference numeral 404 b denotes an element 404 bof the pixel section 414 and the reference numeral 405 denotes a pixelelectrode. Here, the term “element” is referred to a semiconductorelement (typically, TFT) or MIM element or the like used for a switchingelement of pixels in an active matrix type liquid crystal displaydevice. In addition, an active layer of the switching element can beboth a semiconductor having a crystal structure film (polysilicon filmand the like) and a semiconductor film (amorphous silicon and the like)having an amorphous structure.

[0182] First, according to Embodiment 1, n-channel type TFT, one ofwhich electrode is a a pixel electrode, is formed. Further, N-channelTFT and p-channel TFT are formed on the driver circuit 413 respectivelyon the same substrate as the substrate on which the above n-channel TFTwith the pixel electrode is formed. Subsequently, after the activematrix substrate of the state in FIG. 10A was obtained, an orientationfilm 406 a is formed on the active matrix substrate of FIG. 10A, and arubbing processing is performed. It should be noted that in thisembodiment, before the orientation film is formed, a spacer in a columnshape (not shown) for retaining a substrate interval was formed at thedesired position by patterning an organic resin film such as an acrylresin or the like. Moreover, instead of a spacer in a column shape, aspacer in a sphere shape may be scattered over the whole surface of thesubstrate.

[0183] Moreover, in this embodiment, it is preferable that films that ismainly contained Al or Ag or lamination of these films that have wellreflectivity are used for forming a pixel electrode, but when the pixelelectrode is formed by a transparent conductive film, although thenumber of photo-masks increases by one sheet, a transparent type displaydevice can be formed.

[0184] Subsequently, an opposing substrate which is to be a supportingmember 407 is prepared for. A color filter (not shown) in which acolored layer and a shielding layer were arranged corresponding to therespective pixels has been provided on this opposing substrate.Moreover, a shielding layer was provided on the portion of the drivercircuit. A flattening film (not shown) for covering this color filterand the shielding layer was provided. Subsequently, an opposingelectrode 408 consisted of a transparent conductive film was formed onthe flattening film in the pixel section, an orientation film 406 b wasformed on the whole surface of the opposing substrate, and the rubbingprocessing was provided.

[0185] Then, an active matrix substrate 400 in which the pixel sectionand the driver circuit were formed and the supporting member 407 areadhered together with a sealing medium which is to be an adhesive layer409. Into a sealing medium, filler is mixed, two sheets of substratesare adhered together with uniform interval by this filler and a spacerin a column shape. Then, between both substrates, a liquid crystalmaterial 410 is implanted and completely sealed with a sealing compound(not shown) (FIG. 10B). As the liquid crystal material 410, the knownliquid crystal material may be used.

[0186] Next, the substrate 400 provided a nitride layer or a metal layer401 is peeled off by physical means. (FIG. 10C) The substrate 400 can bepeeled off by comparatively small power, because the membrane stress ofthe oxide layer 402 is different from that of the nitride layer 401.

[0187] The film 415 having the heat conductivity is formed on the facethat is peeled off. (FIG. 11A) The film 415 having the heat conductivitycan repair a crack due to peeling. As the film 415 having the heatconductivity, a nitride aluminum (AlN), an oxynitride aluminum (AlNO),and an oxynitride beryllium oxide (BeO) can be used. Further, it ispreferable for the film 415 having the heat conductivity to betransparent film or a translucent film as against visible light. In thisembodiment, the nitride aluminum (AlN) having 2.85 W/cm·K extremely highheat conductivity rate and 6.28 eV (RT) energy gap is formed bysputtering.

[0188] Subsequently, the film 415 having the heat conductivity isadhered with an adhesive layer 411 consisted of an epoxy resin or thelike on a transfer member 412. In this embodiment, the transfer member412 can be made light by using plastic film substrate. In this way, aflexible liquid crystal module is completed. The liquid crystal modulecan prevent an element from deterioration by emitting the generation ofheat occurred by elements 404 a to 404 c by using the film 415 havingthe heat conductivity. The film 415 having the heat conductivity canprevent transformation and a change in quality of a transfer member thatis weak to heat. Then, if necessary, the flexible substrate 412 or anopposing substrate is cut down in the desired shape. Furthermore, apolarizing plate (not shown) or the like was appropriately providedusing the known technology. Then, a FPC (not shown) was attached usingthe known technology. At the time of debonding of the element layerafter bonding of the cover member 620 provided as the supporting member,so that the mechanical strength of this portion is low. Therefore, it isdesirable that the FPC 609 be attached before debonding and fixed by anorganic resin 622. In addition, after that the substrate is peeled off,the opposite substrate is bonded, the wiring drawing portion (aconnecting portion) become only peeled off layer so that the mechanicalstrength become weak. Thus, it is preferable that the peeled off layeris adhered over with FPC before peeling off and fixed with organicresin.

[0189] <Embodiment 6>

[0190] An example of a reflection type of display device in which thepixel electrode is formed of a metallic material having a reflectingproperty has been described as Embodiment 5. This embodiment is anexample of a half-transmission type of display device in which pixelelectrodes are formed of an conductive film having a light-transmittingproperty and a metallic material having a reflecting property, as shownin FIG. 12.

[0191] The step of forming the interlayer insulating layer covering theTFTs and the steps performed before this step are the same as those inEmbodiment 5, and the description for them will not be repeated. One oftwo electrodes in contact with the source region or the drain region ofa TFT is formed of a metallic material having a reflecting property toform a pixel electrode (reflecting portion) 502. Subsequently, a pixelelectrode (transmitting portion) 501 made of a conductive film having alight-transmitting property is formed so as to overlap the pixelelectrode (reflecting portion) 502. As the conductive film having alight-transmitting property, indium-tin oxide (ITO), indium-zinc oxide(In₂O₂-ZnO) or zinc oxide (ZnO), for example, may be used.

[0192] An active matrix board is formed in the above-described manner.The substrate is stripped off from this active matrix board inaccordance with the embodiment mode. A film 507 having thermalconductivity is thereafter formed, a plastic substrate is bonded to theboard by an adhesive, and a liquid crystal module is made in accordancewith Embodiment 5. A backlight 504 and a light guide plate 505 areprovided on the obtained liquid crystal module. The liquid crystalmodule is thereafter covered with a cover 506. An active-matrix liquidcrystal display device such as that partially shown in section in FIG.12 is thereby completed. The cover and the liquid crystal module arebonded to each other by using an adhesive and an organic resin. When theplastic substrate and the opposed substrate are bonded to each other, aspace between the opposed substrate and a frame placed so as to surroundthe opposed substrate may be filled with the organic resin for bonding.Since the display device is of a half-transmission type, polarizingplates 503 are adhered to both the plastic substrate and the opposedsubstrate.

[0193] When a sufficient quantity of external light is supplied, thedisplay device is driven as a reflection type in such a manner thatwhile the backlight is maintained in the off state, display is performedby controlling the liquid crystal between the counter electrode providedon the opposed substrate and the pixel electrodes (reflecting portions)502. When the quantity of external light is insufficient, the backlightis turned on and display is performed by controlling the liquid crystalbetween the counter electrode provided on the opposed substrate and thepixel electrodes (transmitting portions) 501.

[0194] However, if the liquid crystal used is a TN liquid crystal or anSTN liquid crystal, the twist angle of the liquid crystal is changedbetween the reflection type and the transmission type. Therefore, thereis a need to optimize the polarizing plate and the phase differenceplate. For example, a need arises to separately provide an opticalrotation compensation mechanism for adjusting the twist angle of theliquid crystal (e.g., a polarizing plate using a high-molecular weightliquid crystal).

[0195] <Embodiment 7>

[0196] Various modules (active matrix liquid crystal module, activematrix EL module and active matrix EC module) can be completed by thepresent invention. Namely, all of the electronic equipments arecompleted by implementing the present invention.

[0197] Following can be given as such electronic equipments: videocameras; digital cameras; head mounted displays (goggle type displays);car navigation systems; projectors; car stereos; personal computers;portable information terminals (mobile computers, mobile phones orelectronic books etc.) etc. Examples of these are shown in FIGS. 13 and14.

[0198]FIG. 13A is a personal computer which comprises: a main body 2001;an image input section 2002; a display section 2003; and a keyboard 2004etc.

[0199]FIG. 13B is a video camera which comprises: a main body 2101; adisplay section 2102; a voice input section 2103; operation switches2104; a battery 2105 and an image receiving section 2106 etc.

[0200]FIG. 13C is a mobile computer which comprises: a main body 2201; acamera section 2202; an image receiving section 2203; operation switches2204 and a display section 2205 etc.

[0201]FIG. 13D is a goggle type display which comprises: a main body2301; a display section 2302; and an arm section 2303 etc.

[0202]FIG. 13E is a player using a recording medium in which a programis recorded (hereinafter referred to as a recording medium) whichcomprises: a main body 2401; a display section 2402; a speaker section2403; a recording medium 2404; and operation switches 2405 etc. Thisapparatus uses DVD (digital versatile disc), CD, etc. for the recordingmedium, and can perform music appreciation, film appreciation, games anduse for Internet.

[0203]FIG. 13F is a digital camera which comprises: a main body 2501; adisplay section 2502; a view finder 2503; operation switches 2504; andan image receiving section (not shown in the figure) etc.

[0204]FIG. 14A is a mobile phone which comprises: a main body 2901; avoice output section 2902; a voice input section 2903; a display section2904; operation switches 2905; an antenna 2906; and an image inputsection (CCD, image sensor, etc.) 2907 etc.

[0205]FIG. 14B is a portable book (electronic book) which comprises: amain body 3001; display sections 3002 and 3003; a recording medium 3004;operation switches 3005 and an antenna 3006 etc.

[0206]FIG. 14C is a display which comprises: a main body 3101; asupporting section 3102; and a display section 3103 etc.

[0207] In addition, the display shown in FIG. 14C has small andmedium-sized or large-sized screen, for example a size of 5 to 20inches. Further, to manufacture the display part with such sizes, it ispreferable to mass-produce by gang printing by using a substrate withone meter on a side.

[0208] As described above, the applicable range of the present inventionis extremely large, and the invention can be applied to electronicequipments of various areas. Note that the electronic devices of thisembodiment can be achieved by utilizing any combination of constitutionsin Embodiments 1 to 6.

[0209] The film having thermal conductivity in accordance with thepresent invention dissipates heat produced by elements to limitdegradation of the elements and to prevent deformation or and change inquality of a transfer member, e.g., a plastic substrate, thus protectingthe elements. Also, the film having thermal conductivity in accordancewith the present invention prevents mixing of impurities such as waterand oxygen from the outside to protect the elements.

[0210] Even if cracks are caused in the debonded layer at the time ofdebonding the debonded layer from the substrate by a physical means, thecracked portions can be repaired by the film having thermal conductivityin accordance with the present invention, thus improving yield as wellas the reliability of the elements.

What is claimed is:
 1. A light emitting device comprising, on asubstrate having an insulating surface: a light emitting element,wherein the light emitting element comprises a cathode, an organiccompound layer in contact with the cathode, and an anode in contact withthe organic compound layer; an insulating film in contact with theanode; and a film formed in contact with the insulating film, whereinthe film formed in contact with the insulating film comprises highthermal conductivity.
 2. A light emitting device comprising: a substratehaving an insulating surface, a bonding layer in contact with thesubstrate; a film formed in contact with the bonding layer and havinghigh thermal conductivity; an insulating film in contact with the filmhaving high thermal conductivity; and a light emitting element formed onthe insulating film, wherein the light emitting element comprises acathode, an organic compound layer in contact with the cathode, and ananode in contact with the organic compound layer.
 3. A light emittingdevice according to claim 1, wherein the film having high thermalconductivity comprises a film transparent or translucent to visiblelight.
 4. A light emitting device according to claim 2, wherein the filmhaving high thermal conductivity comprises a film transparent ortranslucent to visible light.
 5. A light emitting device according toclaim 1, wherein the film having high thermal conductivity comprising amaterial selected from the group consisting of a nitride containingaluminum, a nitroxide containing aluminum and an oxide containingaluminum.
 6. A light emitting device according to claim 2, wherein thefilm having high thermal conductivity comprises a material selected fromthe group consisting of a nitride containing aluminum, a nitroxidecontaining aluminum and an oxide containing aluminum.
 7. A lightemitting device according to claims 1, wherein the film having highthermal conductivity comprises a film containing at least nitrogen andoxygen, and that a ratio of oxygen to nitrogen in the film is 0.1 to30%.
 8. A light emitting device according to claims 2, wherein the filmhaving high thermal conductivity comprises a film containing at leastnitrogen and oxygen, and that a ratio of oxygen to nitrogen in the filmis 0.1 to 30%.
 9. A light emitting device according to claims 1, whereinthe substrate having an insulating surface comprises a material selectedfrom the group consisting of a plastic substrate and a glass substrate.10. A light emitting device according to claim 2, wherein the substratehaving an insulating surface comprises a material selected from thegroup consisting of a plastic substrate or a glass substrate.
 11. Asemiconductor device comprising: a transfer member; a first bondinglayer in contact with the transfer member; a film formed in contact withthe first bonding layer and having high thermal conductivity; aninsulating film in contact with the film having high thermalconductivity; a layer containing a element on the insulating layer; asecond bonding layer in contact with the layer containing the element;and a supporting member in contact with the second bonding layer.
 12. Asemiconductor device according to claim 11, wherein the supportingmember is an opposed substrate, the element is a thin-film transistorconnected to a pixel electrode, and a space between the pixel electrodeand the transfer member is filled with a liquid crystal material.
 13. Amethod of fabricating a semiconductor device comprising: forming anitride layer on a substrate; forming an oxide layer on the nitridelayer; forming an insulating layer on the oxide layer; forming a layercontaining elements on the insulating layer; bonding a supporting memberto the layer containing elements, and thereafter debonding thesupporting member from the substrate by a physical means at a positionin the oxide layer or at an interface on the oxide layer; forming a filmhaving high thermal conductivity on the insulating layer or the oxidelayer; and bonding a transfer member to the film having high thermalconductivity to interpose the elements between the supporting member andthe transfer member.
 14. A method of fabricating a semiconductor deviceaccording to claim 13, wherein the film having high thermal conductivityis formed of a nitride containing aluminum, a nitroxide containingaluminum, or an oxide containing aluminum.
 15. A method of fabricating asemiconductor device according to claim 13, wherein the nitride layercontains a metallic material.
 16. A method of fabricating asemiconductor device according to claim 13, wherein the metallicmaterial is a single layer of an element selected from the groupconsisting of Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os,Ir, and Pt, an alloy or a chemical compound having the element as a maincomponent, or a multilayer formed of such materials.
 17. A method offabricating a semiconductor device according to claim 13, wherein a heattreatment or a treatment using irradiation with laser light is performedbefore debonding by the physical means.
 18. A method of fabricating asemiconductor device according to claim 13, wherein the oxide layer is asingle layer of a silicon oxide material or a metallic oxide material,or a multilayer of these materials.
 19. A method of fabricating asemiconductor device according to claim 13, wherein the elements arethin-film transistors having a semiconductor layer as an active layer,and forming the semiconductor layer includes crystallizing asemiconductor layer of an amorphous structure by a heat treatment or atreatment using irradiation with laser light to obtain a semiconductorlayer of a crystalline structure.
 20. A method of fabricating asemiconductor device according to claim 13, wherein the supportingmember is an opposed substrate, the elements have pixel electrodes, anda space between the pixel electrodes and the opposed substrate is filledwith a liquid crystal material.
 21. A method of fabricating asemiconductor device according to claim 13, wherein the supportingmember is a sealing member, and the element is a light emitting element.22. A method of fabricating a semiconductor device according to claim13, wherein the supporting member is a film substrate or a basematerial.
 23. A method of fabricating a semiconductor device accordingto claim 13, wherein the transfer member is a film substrate or a basematerial.
 24. A method of fabricating a semiconductor device comprising:forming on a substrate a layer to be debonded, said layer including atleast one semiconductor; bonding a supporting member to the layer to bedebonded; debonding the supporting member from the substrate by aphysical means; and forming a film having high thermal conductivity incontact with the layer to be debonded.
 25. A method of fabricating asemiconductor device comprising: forming on a substrate a layer to bedebonded containing elements; bonding a supporting member to the layerto be debonded; attaching a flexible printed circuit to a portion of thelayer to be debonded; fixing the supporting member by covering aconnection between the flexible printed circuit and the layer to bedebonded with an organic resin; and debonding the supporting member fromthe substrate by a physical means.
 26. A method of fabricating asemiconductor device according to claim 25, further comprising: forminga film having high thermal conductivity in contact with the debondedlayer after the step of debonding; and bonding a transfer member to thefilm having high thermal conductivity to interpose the debonded layerbetween the supporting member and the transfer member.
 27. A lightemitting device comprising: a substrate having an insulating surface; abonding layer in contact with the substrate; a film formed in contactwith the bonding layer and having high thermal conductivity; an oxidefilm in contact with the film having high thermal conductivity; aninsulating film in contact with the oxide film; and a light emittingelement formed on the insulating film, wherein the light emittingelement having a cathode, an organic compound layer in contact with thecathode, and an anode in contact with the organic compound layer.
 28. Asemiconductor device comprising: a transfer member; a first bondinglayer in contact with the transfer member; a film formed in contact withthe first bonding layer and having high thermal conductivity; aninsulating film in contact with the film having high thermalconductivity; a layer containing elements on the insulating layer; asecond bonding layer in contact with the layer containing elements; anda supporting member in contact with the second bonding layer.
 29. Amethod of fabricating a semiconductor device, comprising: forming afirst layer on a substrate; forming a second layer on the first layer;forming an insulating layer on the second layer; forming at least onesemiconductor element over the insulating layer; forming a first bondinglayer over the at least one semiconductor element; bonding a supportingmember to the bonding layer; separating the substrate from thesupporting member by utilizing a stress caused by the first and secondlayers so that the supporting member supports at least the semiconductorelement after the separation; forming a film having high thermalconductivity on an exposed surface over the semiconductor element atwhich the separation of the supporting member occurred; forming a secondbonding layer on the layer having high thermal conductivity; and bondinga transfer member in contact with the second bonding layer so that thesemiconductor element is interposed between the supporting member andthe transfer member.
 30. A method of fabricating a semiconductor deviceaccording to claim 29, wherein the transfer member is a plastic film.31. A method of fabricating a semiconductor device according to claim29, wherein the first layer comprises a nitride of at least one elementselected from the group consisting of Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe,Ni, Co, Ru, Rh, Pd, Os, Ir, and Pt.
 32. A method of fabricating asemiconductor device according to claim 29, wherein the first layercomprises tungsten.
 33. A method of fabricating a semiconductor deviceaccording to claim 29, wherein the film having high thermal conductivitycomprises a material selected from the group consisting of a nitridecontaining aluminum, a nitroxide containing aluminum, and an oxidecontaining aluminum.
 34. A method of fabricating a semiconductor deviceaccording to claim 29, wherein the second layer comprises silicon oxide.35. A method of fabricating a semiconductor device according to claim29, wherein the second layer comprises a metal oxide.
 36. A method offabricating a semiconductor device according to claim 29, wherein thesemiconductor element includes a thin-film transistor, said thin filmtransistor having a semiconductor layer as an active layer
 37. A methodof fabricating a semiconductor device according to claim 29, wherein aheat treatment or a treatment using irradiation with laser light isperformed before separating the supporting member from the substrate.38. A method of fabricating a semiconductor device according to claim29, further comprising a step of forming a pixel electrode in contactwith the semiconductor element and a liquid crystal material over thepixel electrode.